Tissues are widely used for a variety of uses including nose care, removal of cosmetics, eye glass cleaning and wipe ups around the home. Such tissues have gained widespread use for a variety of reasons including the relative inexpensiveness of the product and thus disposability of the tissues.
Such tissue papers require a variety of characteristics depending on their usage. For example softness is a major benefit when the tissue papers are used for nose care or removal of cosmetics. Tissues used for wipe ups, however, generally require absorbency while non-smearing is a preferred benefit when using tissue papers for eyeglass cleaning. Generally speaking most individuals prefer strength of the product for most applications.
Softness of tissues can be imparted to the substrate paper by a variety of means including mechanical and chemical processes. The resiliency, flexibility or smoothness of the tissue may perceive softness of the product.
Mechanical softness may be imparted to the paper by a variety of means including calendarizing which affects the loft or the bulkiness of the paper.
Chemical softness may be imparted to a tissue paper by means of adding or imparting chemical compounds.
For example U.S. Pat. No. 4,950,545 describes facial tissues containing a silicone compound which is incorporated into the tissue with an aqueous carrier having a smear index of 1.0 or less, a lint reduction index of 5 or greater, and sink time no more than 30 second greater than sink time of the same facial tissue without the silicon compound.
Moreover U.S. Pat. No. 5,059,282 teaches a tissue paper comprising cellulostic fibres and an effective amount of polysiloxane material, said polysiloxane being uniformly disposed on the outwardly facing surfaces of the tissue paper, said effective amount of polysiloxane being from about 0.004% to about 2% polysiloxane based on the dry fibre weight of said tissue paper, said polysiloxane having a viscosity of about 25 centistokes or more, said tissue paper after aging two weeks after its manufacture has a wetting time of two minutes or less.
Moreover U.S. Pat. No. 5,552,020 discloses tissue products made by adding one or more softeners/debonders and a silicon glycol copolymer of the paper making fibres at the wet end of the tissue machine, prior to the formation of the tissue web. Suitable softeners/debonders disclosed include organo-reactive polysiloxanes, quaternary ammonium compounds, quaternized protein compounds, phospholipids and silicon quaternaries. One such binder material is starch.
U.S. Pat. No. 5,059,282 also discloses the use of surfactants. Specific surfactants used in tissue paper are disclosed in an article entitled “The Roll of Silicones in Non-Woven Fabric Applications” by A. J. Sabia and R. P. Metzler in NonWovens Industry, September 1983, pp. 16 to 22 namely on page 20,
“Surfactants selected for polymer emulsification can also have an important effect on performance of the organo-reactive silicones.”
The use of a 2% amino-silicone injected into a pulp slurry has been taught in U.S. Pat. No. 5,908,707 where a conventional tissue tissue/towel paper substrate is formed, dried and creped in a conventional manner in the formation of wet-like cleaning wipes.